growing on site of old bonfires.

[dawndaisy]

Now Im more concerned than ever. It hadn't occured to me the soil could be contaminated. I was just concerned that plants might struggle to grow in the soil there. I'll have a chat with my neighbour and see if he remembers the previous plot holder burning anything other than plants.
Thanks for all your ideas. I especially like the idea of growning a green manure that would 'soak up' any residues.
Thanks

[Two_Sheds]

I wouldn't be too worried.

As soon as you light a match on my site, the neighbours are up in arms complaining about the smell. There's no way anyone could get away with burning anything noxious (on our site at least)

[di]

I'm going to be less positive. It will very much depend on what was burned in these bonfires. If it was just garden rubbish and branches etc, no problem. However if it was anything else, the soil could be contaminated with heavy metals or other seriously dangerous substances. If you want to grow on that area, make your concerns known to your Council's environmental health department.

Oh my word AP, should all new plot holders leave their plots fallow for a year or two?

I sort of see your concern BUT, previous plotholders could have burnt or buried or dumped dangerous rubbish on any of our plots.

Perhaps Daisy, it would be worth asking round to check that piles of tyres weren't being burnt.

Once you're happy, depending on your *soil type, I'd get a trug, start filling it and contaminating the rest of your plot with said ash. (when I was working with sandy soil I hated bonfire areas, now I'm clay, the ash works really well to break up the soil)

[salome2001]

The more I think about, the less I would grow anything for human consumption. It is an unknown but there is certainly a known risk. Either check it out or rchuck it out, i.e. the soil and residues from the area of the bonfire site but don't just spread that around in another area. It needs to be disposed of responsibly and that is where the Environmental Health people come in

I burned the stuff on my site and it was just nettles, grass, old rotting wood and a derelict chicken shed. Guess there may have been some treatment on the chicken shed wood, but nothing toxic.

[Aberdeenplotter]

Oh my word AP, should all new plot holders leave their plots fallow for a year or two?

That's not what I have said. We all have the odd bonfire which is a good thing but the situation here was not explained as having the odd bonfire, in fact we were told the previous allotment holder had numerous bonfires. What was burned and where did it come from? I know a single bonfire per year is all I need and I have three half sized plots. If there were numerous bonfires on that plot previously then it does very much call into question what was burned. Neighbouring plotter will not know what was burned, how could they? It seriously needs checking out and to suggest spreading contaminated ash around the plot is quite frankly irresponsible and dangerous.

I agree that none of us know what nasties lie within our plots but I also know that if there was a known unknown as TS nicely put it, that such unknowns need to be checked out. John Selwyn Gummer may well have fed his child meat that could have been contaminated with mad cow disease but that doesn't mean we should knowingly put our own families at risk.

[di]

Why does having numerous bonfires call into question what is being burnt. Several of the Old Boys on our site have a couple a week, I think it's almost a ritual for them...what do they burn? Mainly wood.

Also,if you read my post entirely you will see that I suggested checking what was burnt and 'once you're happy', spread the ash.

He could have had fifty fires, all just pallets, weeds and paper(in which case, the ash would be very beneficial instead of a nuisance). Whoever had your plot before you may have just had the one fire, bang in the middle of your plot and contaminated the soil with all kinds of nasties.

Yes, be cautious, but no need for scare mongering.

[Two_Sheds]

I was told that the previous tenant on my plot was a carpet fitter, and that he burnt all his offcuts on the lotty.

The parts he burned on were in effect kept fallow for a year, simply because it was so hard to dig out all the wire & rubbish that he'd buried there too.

[zazen999]

I'd scrape some of that ash up, pop it in a jam jar [only fill to half full] and top up with warm water, put the lid on and shake.

Then leave to settle.

Open the jam jar.

Sniff - does it smell chemically?

Look at the top of the water - does it have rainbow type oil slicks on it?

Did it bubble up like it would with washing up liquid on top?

Is anything non organic floating on the top?

If no to all, then I'd go ahead and plant in it.

[Two_Sheds]

^ good point there.

Does burnt plastic (carpet) actually turn to ash, or just to lumps?

In textiles, we test unknown fabrics with the 'burn test' ~ natural fabrics (wool, silk, cotton) turn to ash, but synthetics just melt and go into globules

[dawndaisy]

I think the comment about having no real idea about the soil history of our plots is a valid one. Anything could have been put on the soil on any part of my plot, and I would have no idea. I cant avoid growing over this part of my allotment , but I can be cautious and grow non food items for a while. I may change my plan and move my flower garden for the bees and butterflies to this part. But if I do the jam jar test, which I rather like the sound of, and it looks ok, I may go ahead and plant some vegies.
I know the soil at the end of my plot may be contaminated, but think its a low risk. There is, however no visible sign of burnt plastic, no residues of smell of accelarants, and lots of evidence of gardening rubish, such as a burnt trowel, broken pots, and lots of partially burned wood.

I'll ask my neighbour about the previous plot holder, not just what he was burning.

Its hard to strike a balance between sensible awareness of potential problems, and being scared to use my lovely plot.

Thanks for all your thoughts.

[Two_Sheds]

strike a balance between sensible awareness of potential problems, and being scared to use my lovely plot.

That's the way: hear all the pros and cons and make an informed decision based on your own experience/gut instinct

[zazen999]

But if I do the jam jar test, which I rather like the sound of, and it looks ok, I may go ahead and plant some vegies.

I know it's not that scientific - but I tested soil for a living and it's what I would do in the circumstances.

There is probably more yukky stuff in one dose of pesticide or herbicide than the whole of your ash pile.

[Aberdeenplotter]

Why does having numerous bonfires call into question what is being burnt. Several of the Old Boys on our site have a couple a week, I think it's almost a ritual for them...what do they burn? Mainly wood.

Also,if you read my post entirely you will see that I suggested checking what was burnt and 'once you're happy', spread the ash.

He could have had fifty fires, all just pallets, weeds and paper(in which case, the ash would be very beneficial instead of a nuisance). Whoever had your plot before you may have just had the one fire, bang in the middle of your plot and contaminated the soil with all kinds of nasties.

Yes, be cautious, but no need for scare mongering.

And what kind of pallets are burned? Pure fresh wood or pallets dyed goodness knows what colour with goodness knows what to differentiate the use to which they are put, i.e.food use or non food use and what residues are left from burning the non food use ones? Even burning paper can be hazardous because of residues from the ink. We have all seen the fascinating colours when burning magazines but what is causing the colours. You don't know and I don't know and it most certainly isn't scare mongering to advise taking the utmost precautions.

Local authorities have the resources to analyse the soil in a scientific manner and are able to remove and dispose of the remnants from the bonfire site if necessary. It's not something we should be messing about with or taking un-necessary risks with.


The question wasn't asked about my allotments, Daisy asked about a specific issue affecting hers and I have given what I consider to be sensible advice in the circumstances. Daisy is now considering growing non food items in the affected area and that is a very sensible compromise but I would still be calling in the guys with the white coats. I'd also be taking steps to stop the old guys having ritual bonfires. Even if it's not polluting the soil, it is nevertheless contaminating the atmosphere

[oldie]

[QUOTE=Aberdeenplotter;962511] Local authorities have the resources to analyse the soil in a scientific manner and are able to remove and dispose of the remnants from the bonfire site if necessary. And close the whole site down if there is a hint of anything they might consider nasty. Zazen's method is a perfectly acceptable method of soil testing which I know has been recommended by a local(to me) Health&Safety Officer.

[Aberdeenplotter]

Local authorities have the resources to analyse the soil in a scientific manner and are able to remove and dispose of the remnants from the bonfire site if necessary.

And close the whole site down if there is a hint of anything they might consider nasty. Zazen's method is a perfectly acceptable method of soil testing which I know has been recommended by a local(to me) Health&Safety Officer.

Contaminated land « Defra that site seems to set out the current thinking about contaminated land in England. I know I wouldn't be happy if my allotment site was closed down because pollution was found but neither would I be happy to continue growing on it. I'd be mad as hell that someone had been allowed to contaminate it but it would be utterly irresponsible for anyone to want to continue to cultivate in these circumstances.